A toner box is a conventional example of a developer-accommodating vessel provided in an image-forming device for accommodating developer used in image formation. The toner boxes disclosed in above-mentioned patent applications are detachably mounted in a process unit functioning as the developing device of a laser printer.
The developer-accommodating vessel includes an exterior casing having a first toner outlet formed therein, and an interior casing having a second toner outlet formed therein. The interior casing accommodates toner. An agitator is also provided in the interior casing for agitating the toner. The agitator rotates about a rotational shaft passing through the center of the circular interior casing. When the agitator is driven to rotate as the first toner outlet formed in the exterior casing is aligned with the second toner outlet formed in the interior casing, the toner agitated by the agitator in the interior casing is discharged sequentially through the second toner outlet and first toner outlet and is supplied to the process unit side.
A tandem type color printer is a type of image-forming device well known in the art having a plurality of photosensitive drums arranged in parallel and juxtaposed horizontally. This color printer includes a photosensitive drum unit comprising the plurality of photosensitive drums in one cohesive unit, a developing unit disposed below the photosensitive drum unit and functioning to form toner images on the photosensitive drums, and an intermediate transfer belt unit disposed above the photosensitive drum unit for receiving toner images transferred from the photosensitive drums.
The developing unit is provided with a number of developing devices equivalent to the number of photosensitive drums, which developing devices are arranged parallel to each other and juxtaposed horizontally. Each developing device includes a developer case for accommodating toner, and a developing roller disposed at the top of the developer case.
In order to perform maintenance on the photosensitive drum unit and developing unit with the printer, these units can be pulled out from the body of the printer in a horizontal direction following the juxtaposed direction of the photosensitive drums. Once the developing unit has been pulled out of the printer, the individual developing devices can be upwardly extracted from the developing unit.